Means for measuring moisture content of fibrous materials



Feb. 12, 1935- E. J. HAVERSTICK 1,991,093 MEANS FOR MEASURING MOISTURE CONTENEi OF FIBROUS MATERIALS Filed May 31, 1950 Hlll DlUIIHIJUEUCDDDUIIUDMDDFHEINHCDIIEDCCDCUDU.

INVENTOR BY v TTo'RNEY Patented Feb. 12, 1935 UNITED'STATE PATENT oFFics- MEANS FOR. MEASURING MOISTURE CON- TENT or FIBROUS MATERIALS Earl J. Havel-stick, Oakmont, Pa., assignor to Westinghouse Electric & Manufacturing Company, a corporation of Pennsylvania Application May 31, 1930, Serial No. 458,560

4 Claims. (Cl. 73-51) My invention relates to indicators and it has particular relation to indicators used to determine the moisture content of paper or any other fibrous material.

All devices of this character made according to the teachings of the prior art, and with which I am familiar, have had the disadvantages of being somewhat complicated and expensive.

It is, accordingly, an object of my invention to provide an entirely new, simple and inexpensive means for determining the moisture content of a v fibrous material, such as paper.

Although the present invention relates to the fact that the. coeflicient of friction between a moving web of fibrous material and a piece of solid material in frictional engagement with and dragging thereon is a measure of the moisture content of the fibrous material, within certain limits. In my experiments'with a moving web of paper and a. small block of smooth glass, I have foundthat the moisture content of paper is substantially directly proportional to the coefficient of friction between the glass and moving paper when the moisture is within the limits of 4%"and 10%, and sufficiently so for other values of moisture content above and below these values. This principle can; therefore, be used in practical applications since most types of paper have in their final form, a moisture content within the percentage limits mentioned.

The novel features that I consider characteristic of my invention are set'forth with particularity in the appended claims. tion, itself, however, bothas to its organization and its method of operation, together with additionm objects and advantages thereof, wi l best be understood from the following description of a specific embodiment, when read in connection,

with the accompanying drawing, in which:

Figure 1 is a curve showing the relation between the coefficient of friction of a piece of glass on a moving web of paper and the moisture content of thepaper with which the glass is in frictional engagement, I

I Fig. 2 is a diagrammatic side view of the dryer of a paper machine provided with my improved moisture indicator, r

' Fig. ,3 is a plan view .of the dryer and the improved indicator, and

The inven-- Fig. 4 is a perspective view, of a block of solid material and a securing means, constituting a part of my indicator.

The present embodiment of the invention is shown in connection with a dryer of usual construction; including a plurality of heated hollow drums or cylinders 1, about which the paper web passes in a well known manner. The cylinders are heated by steam in the usual manner, the steam being supplied from a manifold 2, which is connected to the respective cylinders at their axes, thereby not interfering with the rotation of the cylinders. Suitable means (not shown) are provided to drive the hollow cylinders 1. The steam leaves the manifold 2 through pipe sections 3, and flows through the rolls 1 into another header 4, and either out into the open air or into a condensingsystem, as may be dev sired.

The plurality of dryerdrum 1 are supported in suitable bearings'inot shown in detail) in a pair of frames 5.

The wet end of the paper machine is not shown I as any usual or desired type may be used, and while I have illustrated and described a specific embodiment of a dryer mechanism, it is to 'be understood that I do not desire to be limited thereto as the device and method embodying my invention hereinafter to be described maybe util-" ized with any machine" making units of fibrous material or with any paper makingand paper drying machine.

I have illustrated a set of calendar rolls 6 rotatably mounted in a frame- '7 and a reel structure 8 on which the web of dried paper 9-may be finally wound.

It is highly desirable if not actually necessary to check the moisture content of the web .of fibrous material and I provide a pair of bracket arms 11, one end of each of which is secured to the end members of the calendar frame '7 and extending toward the dryer rolls. A rod or shaft 12 extends between the bracket arms -11, the ends of the rod or shaft 12 being rigidly mounted on the arms. A screw threaded shaft 13 spaced .from the rod 12 has its ends rotatably supported cured to one end of the shaft to permit of tuming the same.

The rod 12 and the shaft 13 extend parallel to openings extending laterally therethrough to re-" ceive the rod 12 and the screw threaded shaft 13, whereby the carriage is supported above the moveach other and support a carriage 16, having two ing web of paper 9 in such manner as to be movable laterally thereof by turning the crank 14 to eifect'a turning movement of the shaft 13 extending through one of the two openings in the carriage 16. The opening in carriage 16 through which shaft 13 extends has internal screw threads, to cooperate with those on the shaft 13. v A block 17 of solid material, which may be of glass, or preferably of wood, and which may be four inches wide by six inches long and one-half inch or so thick, is placed on the upper surface I of the web 9 in frictional engagement therewith and is yieldingly restrained from movement with the web; by a cord 18 which has one end thereof attached theretoat its rear edgeportion. The

cord 18 passes over two pulleys 19 mounted in spaced relation at the rear portion of the carriage and its other end issecured to a pulley 21 mounted on a shaft 22 of an indicating instrument 23. The shaft 22 is yieldingly restrained from turning by suitable biasing means, such as a spring (not shown). A pointer 24 is secured to the shaft 22 ,and cooperates with a suitable scale whose indicia may indicate either values of the coeificient of friction or more directly the percentage of chanical structure hereinbefore set forth permits of determining in a verysimple and easy manner the drag and, therefore, the friction between a block of solid material and a flat sheet of fibrous material upon relative movement therebe- I tween.

The screw threaded shaft 13 may be rotated by its crank arm 14 to laterally shift the position of the carriage 16 to obtain any desired location of the block 17 on the web-9. If it should be found that there is a variation in the moisture content across the web of material, the carriage-and the solid block of material may be moved laterally of the web of fibrous material to'obtain readings on selected portions of the web or to obtain a number of readings which may be averaged. a

I have found that a block of wood will give excellent results when utilized as the friction member, the indications being constant over long periods of use of such a block of wood and the blockitself being worn to a very small degree by its frictional engagement with the moving sheet of .fibrous material.

desire, therefore, that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention:

1. Means for determining the moisture content of a moving sheet .of fibrous material including a block reposing freely in contact with the moving sheet, means for yieldingly holding the block of material against movement, and an indicator arm actuated'by the holding means for indicating the drag on the block of solid material produced by the moving sheet.

2. In combination, a member presenting a surface to be disposed in frictional contact with a continuously moving web of paper, a biased indicator arm, means for securing said member to said indicator arm, and a scale associated with said indicator arm calibrated in terms of percent moisture.

3. In combination, a block to be disposed on the upper surface of a horizontally moving web of fibrous material, a biasedjndicator arm, and means interconnected between the block and the indicator arm whereby the block is anchored from movement "with the web and the indicator arm is deflected in accordance with the drag exerted on the block by the web.

4. Apparatus for determining the moisture content of a moving Web of material, comprising a member adapted to be placed in contact with the moving material, measuring means connected to said member to be actuated by the frictional drag on said member caused by relative movementbetween said member and material, said measuring means including an indicator calibrated in direct terms of moisture content of the material.

' EARL J. HAVERSTICK. 

